I was wondering: Would it be possible to create an interactive spreadsheet that will play a animated gif when you click an item in the spreadsheet and if so, would it also be possible to save as an iBooks Author widget?

I was basically trying to make an "interactive" japanese hiragana alphabet chart, where if you tap or click on one of the hiragana characters, an animation that depicts how to write that character would play along with the pronounciation of the character via audio. Check this link out to see what I mean: http://www.guidetojapanese.org/learn/grammar/hiragana

Gotchya; in this case I don't think you need a "spreadsheet" in the formal definition (like Excel, Numbers). Instead I'd probably just use elements to make a grid. These elements can have the hiragana inside as characters (they do not need to be images). Each could then have an 'On Mouse Click' action in which it animates and plays audio.